Steam-boiler.



Patented J an. 14, 1919.

J. MCPHAIL.

STEAM BOILER.

APPLICATION FILED ram. 2a, 1918. 1,291,57&

FICE.

JAMES MCPHAIL, OF LOWELLVILLE, OHIO.

STEAM-BOILER.

Application filed February 28, 1918.

To all whom (it 'Ii'ltlj/ mar-era:

to it known that I. Jam-2s l\ICPIl.\1L, a citizen of the United States, residing at llowellville, in the coun-y of hilahoning and State of Ohio, have invented new and useful Improvements in Steam-Boilers, of which the following is a specification.

-l v invention relates to steam boilers of the lire-tube type.

The object of the present; invention is to protect the lire-tubes close to the tube-sheets ol. the boiler. The parts of the lire-tubes surrounded by the tube-sheets not being in contact with water become very hot and if no adequate means is provided to conduct away the heat at these parts, the tubes soon inn-r. through. Another ditlieulty often presents itself also. namely. that the parts of the lire-tubes near the. inner faces of the tubesh ets become incrusted with scale, which being a noneonductoe of heat allows the tubes to be burned through. It is my object to provide means for rapidly conducting the heat from those portions of the firetuhes that are in the tubeheets and to prevent the formation of scale onthose portions of the tire-tubes near the tube-sheets.

Referring to the accompanying drawing. the figure shows a portion of a tube-sheet and a tire-tube in section, the section being taken lougitlulinally and centrally through the fire-tube and through a pair of ferrules between the tube-sheet and the tire-tube.

()u the drawing. 1 designates one of the metalv tube-sheets common to the well known steam boilers used for the generation of steam for power purposes. In such boilers there. is a large number of parallel firetubes having their opposite ends secured in holes in opposing tube-sheets. l have shown only a single fire-tube and only one tubesheet, the complete construction being well known.

2 is a metal fire-tube, through which fire and heat from the fire-box travel to heat water surrouinling the tube. 3 is a ferrule composed of aluminum surrounding that portion of the tube which is surrounded by the tube-sheet.. The ferrule 3 extends into the boiler a short distance, preferably the distance shown on the scale adopted on the drawing. Preferably a shorter ferrule 4 composed of copper surrounds the fire-tube at the portion within the tube-sheet opening 5. The ferrule 4 preferably has only from Specification of Letters Patent.

Patented Jan. 14, 1919.

Serial No. 219.695.

onc-third to one-fourth the length of th aluminum ferrule. and it may be omitted. if desired. The ferrules are heated and shrunk upon the lire-tube in an obvious manner. The lire-tube with the ferrules thereon is secured in the opening 5 in the tube-sheet in any preferred manner, as by heading the outer end at (3 and by rollinga head 7 just inside. the tube-sheet.

The aluminum ferrule is a very good heatcouductor. It takes up the heat conducted to it through the liretube and rapidly conducts it to the water whose currents quickly remove the heat therefrom. At the same time the aluminum prevents the formation of scale on its surface. so that the heat traversingthe aluminum has uninterrupted access to the water surrounding, the ferrule. (opper does not have the property of preventing the formation of scale on its surface. though it is a good conductor of heat. So. if a copper ferrule is used, it should be quite short and thin, as shown. The copper aids to support the aluminum ferrule and prevent the separation of the aluminum. from the tube during the formation of the head 7.

1. In a fire-tube boiler, a tube-sheet having an opening therein, a liret.ub e in the opening, and an aluminum ferrule between the fire-tube and the tube-sheet.

2. la a lire-tube boiler, a tube-sheet having an opening therein, a fire-tube in the opening, and an aluminum ferrule between the fire-tube and the tube-sheet, the ferrule extending beyond the inner face of the tubesheet.

3. In a lire-tube boiler, a tube-sheet having an opening therein, a fire-tube in the opening, and an aluminum ferrule and a copper ferrule .between the fire-tube and the tube-sheet, the copper ferrule surrounding the aluminum ferrule.

4. In a fire-tube boiler, a tube-sheet having an opening therein, a fire-tube in the opening, and an aluminum ferrule between the fire-tube and the tube-sheet, the copper ferrule being relatively thin and covering only a small portion of the aluminum forrule.

Signed at Lowellville, ()hio, this 25th day of February, 19.18.

JAMES MoPl lAIL. 

